The Carl Wunsch Complaint

Carl Wunsch, whose complaint is considered by Ofcom here page 70), is a distinguished scientist. Wunsch read a copy of our GRL paper prior to publication and commented favorably on it, though he was not prepared to provide any public support. A couple of his papers show the peculiar results that red noise series can produce – an approach arguably similar in spirit to our critique of Mannian PC analysis. (In the discussion of the handling of trends in AR4, the position of Wunsch’s opponents is unaccountably preferred to Wunsch’s.) I met Wunsch briefly in San Francisco; he was a mentor to Peter Huybers, who introduced me to him. Many of his quotes in the Ofcom decision are similar to points that I’ve made here.

Ofcom provided an interesting account of how Wunsch got involved with Swindle, which has obviously been a very radicalizing experience for him.

The issues in the Wunsch complaint were different than the accuracy complaint. They were:

1) whether Wunsch was sufficiently informed about the nature of the film to give informed consent. Here they considered Practice 7.3 which stated:

“Where a person is invited to make a contribution to a programme (except when the subject matter is trivial or their participation minor) they should normally, at an appropriate stage: be told the nature and purpose of the programme, what the programme is about and be given a clear explanation of why they were asked to contribute.”

2) whether the programme misrepresented his views, with Ofcom considering separately at the way “the programme presented Professor Wunsch’s general views and those specifically relating to the presence of CO2 in the ocean.” Here Ofcom relied on Practice 7.6 which states that:

“When a programme is edited, contributions should be represented fairly.”

How Wunsch Came to Be Involved
In Sept 2006, the producers sent Wunsch an email, which Ofcom described as follows:

The Committee noted that Professor Wunsch had been contacted initially by the programme makers via email on 15 September 2006. The initial email advised Professor Wunsch that they were producing a programme “about the climate change debate” and that they had read reports about the “effects of climate change on the Great Ocean Conveyor Belt and the Gulf Stream, and wanted to ask if you agree with the conclusions that they are in imminent danger of shutting down”. The letter went on to say that “We are looking for a contributor to talk to us about whether global warming is having a detrimental effect on the oceans or if it is just the case that we don’t yet have enough information to make it a full gone [sic] conclusion”.

Wunsch promptly replied on Sept 18, 2006 referring to a popular representation of the Gulf Stream as a “fairy tale for grown ups”:

He responded that this was “absolutely not” the case, stating that “you can’t turn the Gulf Stream off as long as the wind blows over the North Atlantic and the earth continues to rotate!” and went on to describe the ‘conveyor’ as “a kind of fairy-tale for grownups”. Professor Wunsch said that “I’m willing to talk about these things. I believe that there are all kinds of things happening in the oceans, many highly troubling, but I also believe that one should distinguish what the science tells us and what is merely fantasy”.

It sounds like things started off on pretty friendly terms. Channel 4 said in its evidence (and I saw no evidence that Wunsch denied this):

the programme makers swapped anecdotes with him about the absurd apocalyptic reporting of the global warming scare in the press and TV. Channel 4 said the programme makers also informed the complainant of other contributors who it said were well-known for their critical views on the theory of man-made global warming

The parties had a a telephone conversation, memorialized in a contemporary email (which Ofcom accepted as a plausible rendering of the conversation):

“We are making a feature length documentary about global warming for Channel Four in the UK. The aim of the film is to examine critically the notion that recent global warming is primarily caused by industrial emissions of CO2. It explores the scientific evidence which jars with this hypothesis and explores alternative theories such as solar induced climate change. Given the seemingly inconclusive nature of the evidence, it examines the background to the apparent consensus on this issue, and highlights the dangers involved, especially to developing nations, of policies aimed at limiting growth.”

“We would like to do an interview with you to discuss the notion that there is a scientific consensus on the effects of global warming on the Great Ocean Conveyor Belt, the Gulf Stream and the North Atlantic Drift. It has been widely reported that Britain and Western Europe could soon be plunged into a mini ice age, and we would like to show that this is simply not true that they will shut down.

We would like to talk to you about the numerical models and whether they give us a realistic perspective of the impact of climate change on our oceans. We would also like to talk to you about the ‘memory’ of oceans and how it can take varying amounts of time for a disturbance to be readable in the North Atlantic.

Fundamentally, we would like to ask you whether scientists have enough information about the complex nature of our climate system. Do the records go back far enough to identify climate information about the complex nature of our climate system? Do the records go back far enough to identify climate trends, and can we conclusively separate human induced change from natural change?”

So far, everything seems on track. Ofcom also found that the correspondence made it clear that the producers were approaching things from a “skeptical” viewpoint and this had been made clear to Wunsch:

It was also clear from the correspondence that the programme makers intended to do this through exploring theories which went against the scientific consensus and through looking at the potential dangers (in light of the inconclusive evidence of man-made climate change) of policies aimed at limiting industrial growth. The Committee noted that the recorded interview with Professor Wunsch also proceeded on this basis.

Ofcom examined the unedited and edited interview footage. They determined that the topics discussed with Wunsch were in fact the topics listed in the original email and that these were the same topics that Wunsch is shown commenting on:

The Committee noted from the unedited recording of Professor Wunsch’s interview that these were indeed the topics that were raised with the complainant, and were the same ones which Professor Wunsch was shown commenting on in the programme as broadcast.

The Committee noted a number of Wunsch’s statements, which, on their face, are ones that many CA readers would agree with:

“The models are so complicated you can often adjust them in such a way that they do something very exciting.”

“…So there is a bias, there is a very powerful bias within the media and within the science community itself towards results which are dramatisable [sic].”

“I agree that there’s a very serious risk here [with global warming]. But where I begin to disagree is where people say “the data shows” or “my model proves that”, it’s not at that level.

that it is not yet possible to prove that particular changes in our environment are being caused by human industrial activity, and that the media tended to favour those scientific predictions which warned of disaster.”
”

On many occasions, I’ve observed that, unlike many readers, if I were a policy maker, I would be guided by the advice of major institutions, even if I had personal reservations about the quality of work. Wunsch took a not dis-similar stance:

“most of the time consensus is at least operationally the correct way to proceed, it’s [the issue that is] the need apparently for consensus in the midst of the turmoil of science that is advancing rather more slowly…than we would like.”

So Wunsch obviously contemplated that some sort of “skeptic” production was within the realm of acceptable discourse. Rive and William Connolley would still have hated anything along the lines of what was described in the original Wunsch correspondence. But there was obviously some sort of line that Wunsch felt could be taken. So precisely where did things go awry?

Ofcom Decision
Wunsch’s third and most serious allegation, where he accused the producers of coming “close to fraud”, was characterized by Ofcom as follows:

Professor Wunsch said that the programme makers used his contribution, through its context, to imply that CO2 was all natural, coming from the ocean, and that therefore the human element is irrelevant. Professor Wunsch said he had told the programme makers that a warming ocean could expel more CO2 than it absorbs – thus worryingly exacerbating the greenhouse gas build-up in the atmosphere. Professor Wunsch said that the use of his remarks in this way came close to fraud.

This accusation was rejected in its entirety as follows:

However, in the Committee’s opinion Professor Wunsch’s comments in this respect had not been primarily to warn of the dangers of warming the ocean (as Professor Wunsch had suggested in his complaint). Rather the references had been used to make the point that the relationship between carbon dioxide and atmospheric temperature is complicated. In the Committee’s view, it was entirely at the programme maker’s editorial discretion to decide whether to include these comments in the programme.

In relation to Head b(ii) the Committee therefore found that the programme maker’s editing of Professor Wunsch’s comments about the presence of CO2 in the ocean did not result in unfairness in the programme as broadcast. Accordingly the Committee did not uphold this part of Professor Wunsch’s complaint.

Although Ofcom rejected this complaint, Wunsch’s other two complaints were upheld. Ofcom found that Wunsch had not been adequately warned under Practice 7.3 of the aggressive polemical turn that the production itself would take and for which there was little hint in his correspondence and actual interview. Ofcom:

it found no indication that Professor Wunsch had been informed of the polemical line that the programme would take, for example that the programme would state that the public was “being told lies” and the “scientific evidence does not support the notion that climate is driven by carbon dioxide, man-made or otherwise”. In the circumstances, the Committee considered that Professor Wunsch was not provided with adequate information to enable him to give informed consent for his participation.

While Wunsch may well have been naive, the obligation to comply with Practice 7.3 rested with the producers regardless of potential naivete on Wunsch’s part. I’m sure that Wunsch was bullied by climate scientists of all stripes after the fact, but I’m sure that his complaint was not due to this bullying but to a sincere belief that he had not been properly informed. Under UK legislation, he was entitled to complain to Ofcom and did so. The unfortunate outcome of this seems to have been the radicalization of Wunsch, who now sounds as strident as anyone else, and it will take him a long time to chill out.

The final issue related to whether there had been selective editing that breached Practice 7.6 by forming an inaccurate overall impression of Wunsch’s views was conveyed. Ofcom quoted the following comments from the unedited interview that hadn’t been used, finding that the failure to represent this aspect of Wunsch’s position was unfair in the context of the production.

“So it isn’t the consensus per se that is the issue, and most of the time consensus is at least operationally the correct way to proceed, it’s [the issue that is] the need apparently for consensus in the midst of the turmoil of science that is advancing rather more slowly…than we would like.”

“The consensus that emerges through the IPCC [Intergovernmental Panel on Climate Change] process is generally a reasonable one. But very little of it can actually be proven in the sense that one might say, okay, I can demonstrate to you that Newton’s laws of motion will describe the flight of a ball…”

“I believe a consensus of most scientists who work in climate, given that it is a rather young science, without sufficiently long records, is that there is a very real threat of global warming. Most of the data we have do show that the Earth is warming up, has been warming roughly over the last 100 years. The extent to which this is anthropogenic is the subject of fierce debate. There is a consensus I think of the great majority of scientists that there’s strong evidence that a big part of it, if not most of it, is anthropogenic…And even were it to turn out that it was natural, the threat to humans is very much the same. And one might argue that there has been too much debate about whether it is anthropogenic and whether is it natural and too little attention paid, first of all what are we going to do if this continues to happen? Because there will be real effect on human beings even if it were natural.”

“The healthy science says that, “yeah, there is a working story, but at the same time there are problems with it”, and it’s quite possible that many of the elements that go into the consensus in ten years’ time will be understood actually not to have been true or as accurate as people thought.”

Thus although Ofcom found that the programme fairly represented Wunsch’s view in respect to the matters discussed on air, they found that the exclusion of other views in the context of the program amounted to selective editing. That seems fair enough to me. Lots of people feel that they were ill used in a program but don’t believe that they are in a position to do anything about it. In this case, there was legislation enabling Wunsch to make a complaint. Wunsch did so and received a fair hearing. Would that we’d been so lucky in our FOI requests.

Readers should note that Wunsch’s complaint had nothing to do with the long Rive et al complaint. Wunsch’s complaint was about personal unfairness under Practice 7.3 and 7.6. Ofcom’s findings in respect to Wunsch, which seem reasonable enough to me, have nothing to do with their findings (virtually total rejection) of the Rive complaint – which again seems reasonable enough to me.

Tomorrow, I’ll finish off with a discussion of the IPCC finding, where there is an interesting link to our FOI inquiries.

47 Comments

Wunsch made a rookie mistake. He should have saved his commentary until he had more disclosure from the writers. Channel 4 was disclosing as little as possible in order to increase the probability Wunsch would contribute. Was this underhanded? Yes. Did it violate journalistic integrity rules? No.

The real issue about Wunsch is the quality of his work on ocean dynamics. Read it. He dares to reveal his skepticism vis a vis long-term persistence. Others should be so bold.

bender, in this case, the question was whether the producers had breached Rule 7.3 which stated:

“Where a person is invited to make a contribution to a programme (except when the subject matter is trivial or their participation minor) they should normally, at an appropriate stage: be told the nature and purpose of the programme, what the programme is about and be given a clear explanation of why they were asked to contribute.”

This would appear to be a higher disclosure standard than what you’re describing as “journalistic integrity rules” in which reporters would presumably be allowed to play their cards close to their vest. EVen if Wunsch should have exercised more care, this wouldn’t excuse the producers.

In the overall scheme of things, this is surely pretty small beer and, as noted above, nothing to do with the issues raised in the stuffed Rive complaint,

You could almost say that any program made in this manner deceives some expert somewhere along the line, or selectively edits them enough to make their commentary worthless or say something entirely different. To me Wunsch is just whining. So maybe he should make his own documentary.

#4 Wunsch is free to try to make his case on this thread. He’s not a guy that is prone to whining.

But the social pressure exerted by those distatsteful characters like Bloom has many skeptics knuckling under. They want to deliver their skeptical message, but they don’t want to be perceived as part of a skeptical counter-cultural mass movement. They want a focus on science and scientific uncertainties, not conpsiracy theories and conjectures about motive or intent.

Wunsch says: “I agree that there’s a very serious risk here [with global warming]. But where I begin to disagree is where people say “the data shows” or “my model proves that”, it’s not at that level.”

I find this a bit puzzling. How can AGW be a “very serious risk” when, by his own admission, the evidence available doesn’t support such a conclusion? I can say that the sun going supernova is a serious risk, but I doubt anyone would grow much alarmed by my observation unless I demonstrated its imminence w/ “rigorous” evidence.

I think Wunsch is whining, too, b/c he harbors real doubts about the AGW purported “consensus”, but doesn’t want to be branded a lunatic for straying from the reservation. His desire to keep his sympathy for Steve M’s “GRL” paper private reinforces that suspicion.

I think its telling that a distinguished scientist like Carl Wunsch felt it so necessary to extract a minor apology from the producers of the documentary. It really is a State of Fear in climate science about expressing one’s professional opinion about a scientific matter where such extreme viewpoints delineate that you are either for or against some political position based upon it.

I’d have to say that I disagree (politely, as ever) with Steve about whether it would be prudent to go along with the “consensus” despite personal reservation. I’d say that a politician who didn’t listen to those reservations would be in a very poor position if those reservations were not put to rest.

Putting those reservations to rest would require verification and audit – but who’s going to check when even to check risks spitballs from the mob?

I thought the statements he made were the most ballanced and honest of all of the scientists on the program… then he tried to deny they were made and that he was misrepresented… but TV 4 had him on video, so his attempts to deny them were futile and TV 4 was rightly cleared on the claim of misrepresenting what he said.
Why he claimed to be misrepresented is a different issue and I would give good odds that Steve is right in that Wunsch was bullied by the AGW crowd.

How can AGW be a “very serious risk” when, by his own admission, the evidence available doesn’t support such a conclusion? I can say that the sun going supernova is a serious risk, but I doubt anyone would grow much alarmed by my observation unless I demonstrated its imminence w/ “rigorous” evidence.

But the evidence available now also doesn’t support rejection of the conclusion that AGW is a very serious risk. Reasonably well understood radiative transfer physics says that doubling CO2 and other ghg’s will have some measurable warming effect, i.e. the probability of AGW is not vanishingly small and many reasonable people think the resulting warming could be large enough to have a significant adverse effect on civilization in the near future. After all, there is no question that there has been significant warming in the last 150 years. The current level of warming has, however, almost certainly had a positive effect, but that could change if the temperature increase continues and accelerates.

I actually wrote to Carl Wunsch after his complaint was made. I assured him that from my perspective, he came across as thoughtful and diligent. I sympathised with him that he appeared within a programme as polemical as TGGWS but that his complaint was motivated by professional embarrassment more than being misrepresented. Guilt by association would be an apt summary of this.

Unlike Steve, I think the second complaint seems reasonable, but the third is not.

A documentary, particularly a polemmnic of this nature is video essay of the production and editoral team. It isn’t an open forum to ensure everyone gets to put their views. That is not sustainable regulatory policy.

Wunsch was naive n the extreme if he thought that participating in a documentary is a way of giving the world your opinion, when it is clearly a way of giveing the producers opinion, so long as they do not misrepresent thany contribution from or views of participants (which TGGWS was found not to have done).

Michael Moore wouldn’t have been able to scatch together 2 minutes if such a policy was put in place. And as much as disagree with a lot of what Michael Moore believes and claims, he has every right to use his documentaries to put forward his point of view.

**Thus although Ofcom found that the programme fairly represented Wunsch’s view in respect to the matters discussed on air, they found that the exclusion of other views in the context of the program amounted to selective editing.**
It is impossible to include all of an interview, otherwise the film would take a day to show. It is a bit of grasping at straws to complain about that. If this applied in Canada or USA, it would remove a lot of documentaries, maybe for the better for some of them. Carl’s part one not very controversial, but it looks like the complainants were trying to grasp at every bit they could.

Steve
You mentioned that the use of the word “lie” and “lie” were in your opinion strident and that coplainants should have focussed on such points as this. Whilst the statements were bold and strident, they were in themselves unaguable. There was no suggestion that an individual or an organisation “lied”. but the concept that human induced climate change has been proved beyond doubt. It is clear why the complainants did not want to complain about or be caught justifying their complaint.

Kind of like innocently posting on a science blog, and the next thing you know its a blog discussing “hot girls”:)

Hey, Barclay, maybe we should get together and file a class-action lawsuit against the producers of Climate Audit, for being deliberately misleading about what this blog was about . . .

However, having primarily worked around males for decades now, any conversation, given enough time, will turn to discussing sports, women, or hunting. So, as it is not surprising for ClimateAudit to occasionally stray into subjects such as “hot girls”, you would think that a program designed to be skeptical about AGW would perhaps try to get their point across in every possible way they can think of. Why was Wunsch surprised at this?

the “scientific evidence does not support the notion that climate is driven by carbon dioxide, man-made or otherwise”.

How do you make a critical program about the theory that CO2 drives climate and not have it labelled a polemic if the above is the criteria?

the public was “being told lies”

Who did “Swindle” accuse of lying? There have most assuredly been whoppers told, some of them chronicled here. Did they make false accusations about someone lying? If not how is that polemical? If they did falsely accuse someone of lying then the ‘polemic’ criticism is fair enough.

“Everywhere, you are told, that man-made climate change is proved beyond
doubt….but you are being told lies”;
“it is the story of the distortion of a whole area of science”; and
“it is a story about westerners, invoking the threat of climatic disaster, to hinder
vital industrial progress in the developing world”

“were so sweeping and intemperate that they risked to some degree undermining the
fact that overall the programme very aggressively challenged the mainstream
scientific consensus on man’s contribution to global warming, without concluding that
the mainstream scientific theory was completely without merit.”

This led them to express reservations about their decision that the programme did not breach Rule 2.2, they did fire a shot across the bows though:“As already pointed out Ofcom did have some concerns about aspects of this
programme as regards the portrayal of factual matters and omission of facts or
views. In areas of controversy such as this, broadcasters should exercise an
appropriate degree of caution. This would particularly be the case when scientific
(including medical) issues, with which many viewers will be unfamiliar with the
scientific detail, are dealt with and if there is a material risk of a programme causing
viewers to change their behaviour in a manner which is adverse to themselves or
society in general. In these circumstances, broadcasters should be wary of
presenting a theory or views as fact, or of not providing viewers with sufficient
information so that claims are placed in context. “

1. The science is ‘settled’.
2. This consensus is fully outlined in the IPCC reports.

Suppose these were ‘truths’. Then what do we make of Steve M asking for an “engineering quality description” of the derivation of the CO2 sensitivity coefficients. Is this a charade? Or has he hit upon something that the consensus keepers have “overlooked”?

Phil & Boris: could you please now submit your engineering quality derivations of the CO2 sensitivity coefficient? Please do not cite IPCC. The answers are not there. This “settled science” – where exactly is it housed?

I wish I heard this more from those who say they believe doom is upon us.

—>”The healthy science says that, “yeah, there is a working story, but at the same time there are problems with it”, and it’s quite possible that many of the elements that go into the consensus in ten years’ time will be understood actually not to have been true or as accurate as people thought.”

I regard bender’s comment as inappropriate and representative of his habit of contentless posts, why should I be challenged to make the derivation in support of a quotation of the Ofcom ruling? If bender wants to say that the value used by IPCC is wrong let’s see him derive it that would be a very powerful demonstration of his position. Sauce for the goose is sauce for the gander, if you withdraw my comment I expect you to withdraw bender’s as well.
While we’re on the subject of inappropriate posts how about dealing with Manacker’s accusation of ‘fudging data’ on the ‘Rewriting History’ thread?
Steve: you’re right that bender’s comment is equally inappropriate; yours happened to be at the top of my edit screen and I noticed it. Had bender asked you for the reference to the derivation that you promised to provide, then it would have been appropriate. But as it stands, both of you are taunting.

#31 I ask for an assessment of uncertainty. I echo Steve M’s request for an engineering quality derivation. And this is “contentless”? And “inappropriate”? You will recall I was the first to comment on the Ofcom ruling. Just as I was the first to submit a review of Loehle’s paper. So your claim of “representativeness” seems to ring hollow. You, like borus, bore me to tears.

When you submit to me your engineering quality report, I will then ask for your uncertainty assessment. And then you will see some content on the topic of consensus in science.

The topic here is “lies”. Is the science settled? Monbiot and Phil say it is. So … prove it. My comment was not inappropariate. If you can’t see why it is appropriate, then maybe you should think it over. I don’t have time to write an essay. To think for you. DIY.

Re #31
Thank you Steve. I did provide a reference to a derivation of the log & sqrt dependence of GH gases as I promised before I went one vacation as far as I’m aware it made it on here.
Steve: that was not the derivation of the 3 deg C from doubled Co2 that I understood that you promised. I know that you feel that you promised something less – something that I for one had not requested nor disputed. But I am aware of your position as you are aware of mine – that we still don’t have the reference deriving 3 deg C from doubled CO2.

As I understand Tom Vonk, who I believe has a very good grasp of the physics, we will not see a realistic quantitative derivation of even the CO2 heating effect, let alone the water-vapor feedback effects.

In a sense, there is still taunting. It is well-established by now, I think, that there is no valid derivation of 3 degC sensitivity. A sensitivity of say 1.2 degC is supportable, but the rest is arm-waving and the muttering of “the miracle of positive feedback”.

Steve writes: “Wunsch read a copy of our GRL paper prior to publication and commented favorably on it, though he was not prepared to provide any public support.”
Unfortunate indeed! Regardless of the quality of his own work, that trait may explain the personality of Dr. Wunsch and his predicaments appear as a long overdue consequence of it.

Steve: that was not the derivation of the 3 deg C from doubled Co2 that I understood that you promised. I know that you feel that you promised something less – something that I for one had not requested nor disputed. But I am aware of your position as you are aware of mine – that we still don’t have the reference deriving 3 deg C from doubled CO2.

The discussion you refer to arose out of my disagreeing with Motl’s claim that the log dependence arose from the structure of the atmosphere. I said that that was not correct but that it arose from the spectroscopy and could be demonstrated in vitro, and in any case his mechanism would not explain why some GHGs had linear or square root dependences. I said that it was something that could be found in a graduate level text and was challenged to produce a reference and did so.See here

I believe that in the discussion I also referred to a post of yours from earlier in the year where you commented that the provenance of those expressions was unclear in the IPCC documents? As I recall you posted late in the discussion so we may have been at cross purposes. It was one of those threads that ran over ‘pages’ so the origins may have been missed.

Since you guys brought up the subject of CO2 sensitivity, how about a layman question, being this:

Since the spectral graph of terrestrial IR emissivity taken by satellite shows CO2 notches going to zero, how is it that the addition of atmospheric CO2 can absorb any additional energy? There doesn’t appear to be any appreciable energy left at the relevant wavelengths…

Steve: Expansion of the wings. In my opinion, this is precisely the sort of matter that would be laid out for readers in one of the IPCC reports. Please take anything further to Unthreaded.

#42. That’s true, but Michael Moore wasn’t operating under Ofcom regulations. Which poses an interesting question though – if a Michael Moore documentary were shown in the UK, would the various ambushed partis have the right to complain to Ofcom? It seems to me that they would.

I wonder if the Carl Wunsch ruling will limit the ability of UK channels to show things like the Michael Moore documentaries. Seems likely to me.

There’s an old legal saying – hard facts make bad law. That may just have happened.

Thank you Steve. I did provide a reference to a derivation of the log & sqrt dependence of GH gases as I promised before I went one vacation as far as I’m aware it made it on here.

If making an vague appeal to spectrum line broadening qualifies as “provid[ing] a reference to a derivation of the log & sqrt dependence” then…you still failed to provide a reference, since as I pointed out at the time, the relationships given by equivalent line width is linear, sqrt(log) (not log), and sqrt. See, for example, here.

If making an vague appeal to spectrum line broadening qualifies as “provid[ing] a reference to a derivation of the log & sqrt dependence” then…you still failed to provide a reference, since as I pointed out at the time, the relationships given by equivalent line width is linear, sqrt(log) (not log), and sqrt. See, for example, here.

Actually I gave a text reference as requested, it was the last thing I did en route to my vacation.
The two limiting conditions are linear and Sqrt in between there’s a flattening off region and depending what assumption you make you can get different dependences.

Phil, I’ve never seen anything other than sqrt(log) for the middle region, which I’ve seen from several sources. In your original comment, you cited as a reference Spectrophysics 2nd Ed. by A. P. Thorne, Chapman & Hall. Since you didn’t quote the section you refer to, and since I don’t have access to that text*, I can’t comfirm or rebut your claim. However, you now say about the curve of growth, “in between there’s a flattening off region and depending what assumption you make you can get different dependences.” This doesn’t seem consistent with the claim that the supposed log response curve to CO2 is a consequence of spectral broadening unless you can show that the flattening off region for CO2 is logarithmic. So unless Spectrophysics specifically make that claim, I don’t see how you can cite it as a reference for that assertion.

Phil, Whomsoever shall claim the science being settled should/shall provide the clear exposition of the effects of CO2 on temperature, not vice-versa. You seem to have your logic twisted in this case. When you extort upon Bender to provide his own exposition, it is merely your attempt at obfuscation, which from the AGW camp is typical.
Why don’t you copy and paste your references, and exposition, if you have them at your fingertips, instead of linking to irrelevant texts?